Reactor and processes for endothermic reactions at high temperatures

ABSTRACT

An endothermic catalytic reactor apparatus that includes a radiant furnace that includes a burner adapted to provide thermal energy to the furnace, a reactor that includes an entrance portion and an exit portion and is situated within the furnace and adapted to receive radiant thermal energy. The reactor includes one or more static helical spirals defining a flow path within the reactor that travels from the entrance portion to the exit portion. The helical spirals are adapted to hold a catalyst on an outer surface thereof. Incoming port(s) are located on the entrance portion and are adapted to receive reactive starting materials. An exit port is located near the exit portion and is adapted to expel product from the reactor. The reactor is adapted to allow starting materials to receive radiant thermal energy and interact with catalyst sufficiently to cause a reaction to occur that converts starting materials to product.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/315,808 filed on Mar. 2, 2022, which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure is directed to an endothermic catalytic reactorapparatus that includes a furnace and a reactor.

BACKGROUND

An endothermic process is any process with an increase in the enthalpyor internal energy of a system. In such a process, a closed systemusually absorbs thermal energy from its surroundings, which can be heattransfer into the system. For example, if more energy is needed to breakbonds than the energy being released, energy is taken up, and anendothermic reaction results.

SUMMARY

The present disclosure provides an endothermic catalytic reactorapparatus that includes a radiant furnace and an endothermic reactor.The radiant furnace includes a burner adapted to provide thermal energyto the furnace. The reactor has an entrance portion and an exit portionand is situated within the furnace and adapted to receive radiantthermal energy from the furnace. The reactor includes one or more statichelical spirals defining a flow path within the reactor so that amaterial can follow the defined flow path to travel from the entranceportion to the exit portion. The helical spirals are adapted to hold acatalyst on an outer surface thereof. One or more incoming ports arelocated on the entrance portion and are adapted to receive reactivestarting materials. An exit port is located on or near the exit portionand is adapted to expel product from the reactor. The reactor is adaptedto allow the starting materials to receive radiant thermal energy andinteract with the catalyst sufficiently to cause a reaction to occurthat converts starting materials to product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view schematic of a reactor apparatusaccording to this disclosure.

FIG. 2 is a front elevation view schematic of a reactor apparatusaccording to this disclosure.

DETAILED DESCRIPTION

It is to be understood that this disclosure may assume variousalternative variations and step sequences, except where expresslyspecified to the contrary. As a nonlimiting example, FIGS. 1 and 2 showthe axis of reactor 105 in a vertical position and the reactant flowproceeding downward, but this is not a requirement. The axis of reactor105 can be vertical, horizontal or any orientation appropriate forimplementation. Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that can vary depending upon thedesired properties to be obtained. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the disclosure are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

All ranges are inclusive and combinable. For example, the term “a rangeof from 0.06 to 0.25 wt. %, or from 0.06 to 0.08 wt. %” would includeeach of from 0.06 to 0.25 wt. %, from 0.06 to 0.08 wt. %, and from 0.08to 0.25 wt. %. Further, when ranges are given, any endpoints of thoseranges and/or numbers recited within those ranges can be combined withinthe scope of the present disclosure.

As used herein, unless otherwise expressly specified, all numbers suchas those expressing values, ranges, amounts or percentages can be readas if prefaced by the word “about”, even if the term does not expresslyappear. Unless otherwise stated, plural encompasses singular and viceversa. As used herein, the term “including” and like terms means“including but not limited to”.

As used herein, the transitional term “comprising” (and other comparableterms, e.g., “containing” and “including”) is “open-ended” and open tothe inclusion of unspecified matter. Although described in terms of“comprising”, the terms “consisting essentially of” and “consisting of”are also within the scope of the disclosure.

As used herein, the articles “a”, “an”, and “the” include pluralreferences unless expressly and unequivocally limited to one referent.

As used herein, the term “defined path” refers to the spiral pathway(s)through a reactor defined the surfaces of the helical spiral(s) and thedistance from the inner side of the wall of the reactor and the outersurface of an optional central shaft extending along the central axis ofthe reactor.

As used herein, the term “endothermic reactor” refers to a reactoradapted to allow a chemical reaction to take place that absorbs thermalenergy or heat from its environment. The absorbed energy provides theactivation energy for the chemical reaction to occur.

As used herein, the term “helical spiral” refers to a spiral blade thatcan be coiled around a shaft. While a central shaft can be used toconstruct and maintain the helical spiral, it is not required for theprocess. The coiling simply needs to be such that there is no centerhole for the process stream to short-circuit.

As used herein, the term “linear velocity” refers to the distance a gaswill travel in a given time.

As used herein, the term “mass flow rate” refers to the mass of a liquidsubstance passing per unit of time. SI units are kilogram per second.The mass flow directly depends on the density, velocity of the liquid,and the area of the cross-section. Mass flow rate can be determinedaccording to the equation:m=ρVAwhere, ρ=density of fluid, V=velocity of liquid, and A=cross sectionalarea.

As used herein, the term “Nusselt number” refers to the ratio ofconvective to conductive heat transfer at a boundary in a fluid. ANusselt number of value one represents heat transfer by pure conduction.A value between one and 10 is characteristic of laminar flow. A largerNusselt number corresponds to more active convection, with turbulentflow typically in the 100-1000 range.

As used herein, the term “radiant furnace” refers to as a direct heateror a direct fired heater used to provide thermal energy or heat for areactor. They are used to provide heat for a process. The radiantfurnace design can vary as to its type of fuel and method of introducingcombustion air. Heat is generated by mixing fuel with air or oxygen, orfrom electrical energy. The residual heat can exit the furnace as fluegas.

As used herein, the term “Reynolds number” refers to the dimensionlessratio of inertial forces to viscous forces within a fluid which issubjected to relative internal movement due to different fluidvelocities. The Reynolds number helps predict flow patterns in differentfluid flow situations. At low Reynolds numbers, flows tend to bedominated by laminar flow, while at high Reynolds numbers flows tend tobe turbulent. When the Reynolds number is less than about 2,000, flow ina pipe is generally laminar, whereas, at values greater than 3,000, flowis usually turbulent.

As used herein, the term “volumetric flow rate” refers to the fluidvolume that passes a specified point per unit of time. Volumetric flowrate can be determined according to the equation:Q=AVwhere Q is the volume flow rate, A is the cross-sectional area occupiedby the flowing material, and Vis the average velocity of flow.

Disclosed herein is an endothermic catalytic reactor apparatus thatincludes a radiant furnace and a reactor. The radiant furnace includes aburner adapted to provide thermal energy to the furnace. The reactor hasa reactant entrance and an exit, is situated within the furnace andadapted to receive radiant thermal energy from the furnace. Within thereactor are one or more static helical spirals positioned within thereactor so that a material can follow a defined path to travel from thereactant entrance to the exit. The helical spirals are adapted to hold acatalyst on an outer surface thereof. One or more incoming ports arelocated on the entrance portion of the reactor and are adapted toreceive reactive starting materials. The reactor includes one or moreexit ports on or near an exit portion, which are adapted to expelproduct from the reactor. The reactor is adapted to allow the startingmaterials to receive radiant thermal energy and interact with thecatalyst sufficiently to cause a reaction to occur that convertsstarting materials to product.

As shown in FIG. 1 , reactor apparatus 100 includes endothermic reactor105 and radiant furnace 110 (in dashed lines), which includes flue 108.Reactants are provided to endothermic reactor 105 through reactant feedline 120 and can be optionally heated by flowing through optional heatexchanger 130 and optional heat exchanger 180 and subsequently emptyinginto endothermic reactor 105 at the entrance portion 135 of reactor 105(heat exchangers 130 and 180 are optional and can be utilized dependingon the process to be carried out in reactor 105). As shown, reactantfeed line 120 travels through shell side 182 of heat exchanger 180 andmaterial travels in the direction of arrow 183. Radiant furnace 110encases substantially all of endothermic reactor 105 and includes burner140 (shown with dashed lines) which can combust a flammable materialfrom line 145 or, alternatively, be an electric heating element withinradiant furnace 110.

Endothermic reactor 105 includes static helical spiral 150 that includesa defined path positioned within endothermic reactor 105 around centralshaft 107 and adapted to allow reactants to follow the defined path totravel from entrance portion 135 to product discharge 160. Helicalspiral 150 has a thickness 157 described herein. Helical spiral 150 canbe adapted to contain a catalyst on an outer surface thereof, firstsurface 162 and second surface 164. Radiant furnace 105 providessufficient thermal energy to allow reactants to be converted to producteither through direct conversion or catalyzed reaction throughinteraction with the catalyst contained on the first and second surfaces162 and 164 of helical spiral 150. The effluent from product discharge160 passes through tube 184 of heat exchanger 180 in the direction ofarrow 183, heating the contents of reactants in shell side 182.Reactants can be sufficiently heated to be in a gaseous or vapor stateleaving heat exchanger 130 and heated to near reaction temperature whenleaving heat exchanger 180 and entering endothermic reactor 105.

The flows through heat exchanger 180 can be countercurrent as shown inFIG. 1 where reactants flow through reactant feed line 120 in adirection shown as first flow direction 181 and a product stream flowsthrough product discharge line 160 in a direction shown as second flowdirection 182.

Catalysts can be employed as described herein to increase the reactionrate of the process in reactor 105. The catalysts may not change themaximum conversion at a given temperature. In some cases, given theefficient energy transport accompanying the highly turbulent helicalreactant flow and the elevated temperatures achievable with radiantfurnace 110, direct conversion, such as acceptable process performancecan be obtained without a catalyst.

The product leaving tube 184 of heat exchanger 180 can be separated inseparator 170 which can produce several separated streams shown asnonlimiting exemplary streams 172, 174 and overhead stream 188. One ofstreams 172 and 174 may be a primarily organic stream and the other maybe an aqueous stream. Non-condensable materials can be removed inseparator 170 via overhead stream 188. When the non-condensablematerials are flammable material, they can be used in in burner 140 whenit is a combustion burner after either being mixed with other flammablematerials or used alone in line 145.

As shown in FIG. 2 , where features in FIG. 1 that are similar arenumbered the same, reactor apparatus 200 includes endothermic reactor105 and radiant furnace 110 (in dashed lines), which includes flue 108.Reactants are provided to endothermic reactor 105 through reactant feedline 120 and can be optionally heated by flowing through heat exchanger130 and optional heat exchanger 180 and subsequently emptying intoendothermic reactor 105 at the entrance portion 135 of reactor 105. Asshown, reactant feed line travels through shell side 182 of heatexchanger 180 and material travels in the direction of arrow 183.Radiant furnace 110 encases substantially all of endothermic reactor 105and includes burner 140 (shown with dashed lines) which can combust aflammable material or, alternatively, be an electric heating elementwithin radiant furnace 110.

Endothermic reactor 105 includes first static helical spiral 150 andsecond helical spiral 152, which can be positioned within endothermicreactor 105 around central shaft 107 and adapted to allow reactants tofollow a defined path to travel from entrance portion 135 to productdischarge 160. The helical spirals 150 and 152 can have a thickness 158and 157 respectively described herein. The defined path can be adaptedto contain a catalyst on an outer surface thereof, first and thirdsurfaces 162 and 166 and second and fourth surfaces 164 and 168respectively. Radiant furnace 105 provides sufficient thermal energy toallow reactants to be converted to product either through directconversion or catalyzed reaction through interaction with the catalystcontained on first, second, third and fourth surfaces 162, 164, 166 and168 of helical spirals 150 and 152. The effluent from product discharge160 passes through tube 184 of heat exchanger 180 in the direction ofarrow 183, heating the contents of reactants in shell side 182.Reactants can be sufficiently heated to be in a gaseous or vapor stateleaving heat exchanger 130 and heated to near reaction temperature whenleaving heat exchanger 180 and entering endothermic reactor 105.

The flows through heat exchanger 180 can be countercurrent as shown inFIG. 1 where reactants flow through reactant feed line 120 in adirection shown as first flow direction 181 and a product stream flowsthrough product discharge line 160 in a direction shown as second flowdirection 182.

The product leaving tube 184 of heat exchanger 180 can be separated inseparator 170 which can produce several separated streams shown asnonlimiting exemplary streams 172, 174 and overhead stream 188. One ofstreams 172 and 174 may be a primarily organic stream and the other maybe a primarily aqueous stream. Non-condensable materials can be removedin separator 170 via overhead stream 188. When the non-condensablematerials are flammable material, they can be used in in burner 140 whenit is a combustion burner after either being mixed with other flammablematerials or used alone in line 145.

As shown in FIGS. 1 and 2 , the spiral flow along the defined path andagainst the reactor wall at high velocity can provide excellent energytransfer between the reactor wall and reactants regardless of reactororientation (vertical, horizontal or sloped). This wall-to-reactanttransfer can be so efficient that the overall transfer between theradiant furnace and reactants may be limited only by the thermalconductivity and thickness of the reactor wall.

The starting materials can pass through a heat exchanger prior toentering reactor 105 so they enter reactor 105 in a gaseous or vaporstate at a temperature of from 225° C., such as 275° C., 325° C. or 425°C. and can be up to 725° C., such as 675° C. or 625° C. The temperatureof the starting materials entering reactor 105 can be any value or rangebetween any of the values recited above.

The starting materials can be mixed with super-heated steam prior toentering reactor 105 in order to aid in achieving desired temperaturesand flow properties while traversing the defined flow path throughreactor 105.

The dimensions of endothermic reactor 105, the defined path throughendothermic reactor 105 and the flow rate of reactants, or startingmaterials, into reactor 105 and the flow rate of product out of reactor105 can be tailored to the specific process to be employed therein. As anonlimiting example, reactant feed line 120 can empty into reactor 105through a port that can have any suitable cross-sectional shape,nonlimiting examples being circular, oval, square, rectangular orparallelogram. Other suitable shapes of reactor 105 include a barrelshape or an hour-glass shape. The cross-sectional area of the port canbe at least 0.5 m², such as 1 m² or 2 m² and can be up to 6 m², such as5 m² or 4 m². The cross-sectional area of the port for startingmaterials entering reactor 105 can be any value or range between any ofthe values recited above.

Reactor 105 can be cylindrical and enclosed at both ends. As indicated,reactor 105 can include a static helical spiral as shown in FIG. 1 or astatic helical spiral with multiple parallel spirals, as shown in FIG. 2with two parallel spirals. There are ports at each end to receive anddischarge the reactant stream. The spirals can extend from an optionalcentral spine to the generally cylindrical wall. The wall can be made ofmetal with high thermal conductivity and the minimal thickness requiredfor stability at the reaction temperature. Reactor 105 is adapted toallow the starting materials to receive radiant thermal energy andinteract with the catalyst sufficiently to cause a reaction to occurthat converts starting materials to product. The helical spiral—reactorwall combinations can allow reactant flow at high velocities, i.e.,turbulent, against the reactor wall, which can affect the energytransport between the wall and the reactant stream.

The inner diameter of reactor 105 and can be selected based on thespecific process to be employed therein. The reactor diameter can be atleast 1 m, such as 3 m or 4 m and can be up to 10 m, such as 7 m or 4 m.The diameter of reactor 105 can be any value or range between any of thevalues recited above.

With many shapes for reactor 105, the reactor walls can be tapered,which can reduce leakage where the edge of the spiral meets the wall.This configuration is similar to a fitted tapered stopper and reducesleakage compared to one with straight sides.

When reactor 105 is barrel or an hour-glass shape, the spiral helix canbe built first and then reactor walls can be wrapped “mummy-fashion”around the spiral helix.

The single spiral shown in FIG. 1 can alternatively be accomplishedwithout central shaft 107. This alternative approach can be used whenthe width of the helical surface is wide enough to cover the reactordiameter, thus avoiding a short circuit along the central axis.

The helical spirals, shown as 150 and 152 in FIGS. 1 and 2 can make anysuitable number of revolutions so long as they originate at reactantfeed line 120, which provides reactants or starting materials to reactor105 and terminate at product discharge 160. The helical spirals can makeat least 1.5, such as 2 or 2.5 revolutions and can make up to 6.5, suchas 5.5, 5, or 4.5 revolutions. The number of revolutions of the helicalspirals can be any value or range between any of the values recitedabove. As those skilled in the art can appreciate, a 0.5 revolutionplaces reactant feed line 120 and product discharge 160 on the same sideof reactor 105, while a full revolution placed reactant feed line 120and product discharge 160 on opposite sides of reactor 105. The numberof revolutions of the helical spirals will depend on the process to beemployed and the position and orientation of reactor 105 and associatedequipment.

The width of the helical spirals 150 and 152 can be the same, or nearlythe same as the inner diameter of reactor 105 such that there is asufficient fit between the spiral edge and the wall of reactor 105 sothat leakage of reactants or starting materials from the desired helicalflow (defined path) is minimized.

The pitch of helical spirals, shown as 150 and 152 in FIGS. 1 and 2 ,can be whatever pitch allows the helical spirals to traverse from thereactant feed line 120 provides reactants or starting materials toreactor 105 and to product discharge 160 and can be selected based onthe specific process to be employed therein. The pitch of the helicalspirals can be at least 0.25 m, such as 0.5 m or 0.75 m and can be up to5 m, such as 4 m, 3 m or 2 m. The pitch of the helical spirals can beany value or range between any of the values recited above.

Reactor 105, helical spirals 150 and 152 and the other components ofreactor apparatus 100 and reactor apparatus 200 can be constructed ofany material that will be stable in the presence of the process to beperformed therein, not degrade due to the temperatures and pressuresemployed. Nonlimiting examples of suitable materials of constructioninclude 304 stainless steel, 316 stainless steel, 316L stainless steel,copper, aluminum, Alloy A-286, Alloy 20, Alloy 230, Alloy 400, Alloy600, Alloy 625, Alloy B-2, Alloy B-3, Alloy C-276, Nickel 200, TitaniumGrades 2, 3, 4, and 7, Zirconium 702, Zirconium 705 and combinationsthereof. The walls of reactor 105 can be made from a material ofsuitably high thermal conductivity, such as copper or aluminum such thatthe walls readily transfer thermal energy or heat from the furnace tothe contents of reactor 105.

As indicated above, the one or more helical spirals, shown as 150 inFIGS. 1 and 150 and 152 in FIG. 2 , can be adapted to contain a catalyston an outer surface thereof, shown as upper sides 162 and 166 and undersides 164 and 168 respectively. The particular catalyst will varydepending on the process to be performed in reactor 105. As nonlimitingexamples, the catalyst can be deposited on the outer surface andthermally aged; embedding catalyst containing nanoparticles on the outersurface through a redox reaction at a solid-solution interface;embedding the catalyst in an abraded, perforated, or stiff mesh materialinstalled on the outer surface; supporting a catalyst on a stablesupport material with a high specific surface area, nonlimiting examplesincluding alumina, silica, zeolite, and carbon, which enables the highspecific surface area of the catalyst to be maintained with highcatalytic activity; and other methods known in the art. Regardless ofhow the catalyst is held to the outer surface, the catalyst will beseparate from and not impede the defined flow path so that high volumesand high flow rates, as described above, can be maintained.

The thickness of the helical spirals, shown as 157 in FIGS. 1 and 2 ,can be any thickness that provides sufficient structural integrity tothe helical spiral in the desired process, but not so thick as to impedeheat transfer or the defined flow path. As a nonlimiting example, thethickness of the helical spirals can be 0.3 cm, such as 1 cm or 2 cm andcan be up to 5 cm, such as 4 cm. The thickness of the helical spiralscan be any value or range between any of the values recited above.

Reactor 105 can include multiple helical spirals as shown in FIG. 2 ,where two helical spirals 150 and 152 are shown. When multiple helicalspirals are employed, the spacing between one helical spiral and thenearest helical spiral will often be equidistant to provide the mostefficient flow along the defined path. The spacing between helicalspirals can vary from equidistant, however flow efficiency may bedecreased as a result.

As shown in FIG. 2 , product discharge 160 provides a path for an exitstream from both of the two parallel spirals 150 and 152, where bothdischarge into product discharge 160 in order to exit reactor 105.

The starting materials or reactants can optionally include steam toachieve desired physical parameters as described below. The ratio ofsteam to starting materials or reactants can be at least 0.25:1, such as0.5:1 or 0.75:1 and can be up to 4:1, such as 3:1, 2:1 or 1.5:1. Theratio of steam to starting materials or reactants can be any value orrange between any of the values recited above.

The pressure in reactor 105 can be any pressure that facilitates theflow or starting materials or reactants along the defined path andencourages conversion or reactants to product. The pressure in reactor105 can be at least 0.25 atm, such as 0.5 atm or 0.75 atm and can be upto 10 atm, such as 8 atm, 6 atm, 4 atm or 2 atm. Appropriate valves andcompressors as are known to those skilled in the art can be employed toachieve and regulate a desired pressure. The pressure in reactor 105 canbe any value or range between any of the values recited above.

The starting materials and optional steam can have a mass flow ratethrough reactor 105 of from 20 kg/sec, such as 25 kg/sec or 30 kg/secand can be up to 150 kg/sec, such as 140 kg/sec or 125 kg/sec. The massflow rate for the starting materials and optional steam flowing throughreactor 105 can be any value or range between any of the values recitedabove.

The starting materials and optional steam can have a volumetric flowrate through reactor 105 of from 500 l/sec, such as 600 l/sec or 700l/sec and can be up to 1,0001/sec, such as 900 l/sec or 500 l/sec. Thevolumetric flow rate for the starting materials and optional steamflowing through reactor 105 can be any value or range between any of thevalues recited above.

The starting materials and optional steam can have a linear velocitythrough reactor 105 of from 15 m/sec, such as 20 m/sec or 25 m/sec andcan be up to 35 m/sec, such as 33 m/sec or 30 m/sec. The linear velocityfor the starting materials and optional steam flowing through reactor105 can be any value or range between any of the values recited above.

The dimensions of the defined path through endothermic reactor 105 andthe flow rate of reactants, or starting materials, into reactor 105 andthe flow rate of product out of reactor 105 are designed to achieveparticular flow parameters. As a nonlimiting example, the startingmaterials are gaseous when entering reactor 105 and flow along thedefined path such that the starting materials have a Reynolds number offrom 1,000,000, such as 2,000,000 or 3,000,000 and up to 15,000,000,such as 12,500,000 or 10,000,000. The Reynolds number for the startingmaterials flowing through reactor 105 can be any value or range betweenany of the values recited above.

As a nonlimiting example, the starting materials are gaseous whenentering reactor 105 and flow along the defined path such that thestarting materials have a Nusselt number of from 3,000, such as 4,000 or5,000 and can be up to 15,000, such as 12,500 or 10,000. The Nusseltnumber for the starting materials flowing through reactor 105 can be anyvalue or range between any of the values recited above.

The radiant furnace 110 included in reactor apparatus 100 and reactorapparatus 200 can generate any suitable temperature for the process tobe employed therein, which can include a temperature of from 350° C.,such as 400° C. or 450° C. and can be up to 900° C., such as 850° C.,800° C. or 750° C. The radiant furnace temperature can be any value orrange between any of the values recited above.

As indicated above, the starting materials can be gaseous when enteringreactor 105 and flow along the defined path. The thermal energy or heatfrom the furnace can be readily transferred to the contents of reactor105 and the high flow rates, as indicated by the Reynolds number andNusselt number, provide sufficient and constant turnover at thecatalytic surface of the helical spirals to allow starting materials tobe converted to product.

The conversion of starting materials to product in reactor 105 will varydepending on the process and process conditions employed and can be atleast 10%, such as 25%, 40%, 50%, 60%, 70%, 75% or 80% and can be up to100%, such as, 99%, 95% or 90%. The conversion of starting materials toproduct can be any value or range between any of the values recitedabove.

An exit stream that includes product and optionally unreacted startingmaterials, optionally non-condensable materials and optional steam exitsreactor 105 via line 160 and can enter heat exchanger 180. For ease ofdescription, heat exchanger 180 is shown in a vertical orientation inFIGS. 1 and 2 , roughly parallel with reactor 105. Especially in highvolume applications, heat exchanger 180 can be in a horizontalorientation. The exit stream can be directed to tube side 184 of heatexchanger 180 flowing in the direction of arrow 183, where it can beused to heat starting materials or reactants transported from reactantfeed line 120 to shell side 182 of heat exchanger prior to enteringentrance portion 135 of reactor 105. The relative flow patterns in shellside 182 and tube side 184 can be in the same direction or in oppositeor countercurrent directions depending on the process employed. The exitstream leaves tube 184 of heat exchanger 180 and enters separator 170.Separator 170 separates the exit stream into several separated streamsshown as nonlimiting exemplary streams 172, 174 and overhead stream 188.One of streams 172 and 174 contain a primarily organic stream and theother a primarily aqueous stream. Non-condensable materials can beremoved in separator 170 via overhead stream 188. When thenon-condensable materials are flammable, they can be used in in burner140 when it is a combustion burner after either being mixed with otherflammable materials or used alone in line 145.

Conventional methods, such as distillation towers, can be used toisolate unreacted starting materials or reactants from product in theprimarily organic stream and any unreacted starting materials orreactants from water in the primarily aqueous stream. The product canthen be packaged as appropriate, the unreacted starting materials orreactants can be returned to reactant feed line 120 and the water can beregenerated into steam or super-heated steam and used as describedabove.

Thus, the present disclosure provides a method of converting reactantsto product that includes passing reactants through a heat exchanger toprovide heated reactants, that can be in a gaseous or vapor state andoptionally include super-heated steam as described above at thetemperatures described above; providing heated reactants to theendothermic catalytic reactor apparatus described above that can includea radiant furnace, as described above, that includes a burner, asdescribed above, and adapted to provide thermal energy or heat to thefurnace; a reactor, having any of the configurations described above,having a reactant feed line and a product discharge, situated within thefurnace and adapted to receive radiant thermal energy or heat from thefurnace; one or more static helical spirals adapted to hold catalyst asdescribed above, positioned within the reactor so that material canfollow a defined path from the reactor feed line to the productdischarge; one or more incoming ports on the entrance portion, adaptedto receive the reactants from the reactant feed line; and a productdischarge port on or near the exit portion, adapted to expel productfrom the reactor; where the reactor is adapted to allow the reactants toreceive radiant thermal energy and interact with the catalystsufficiently to cause a reaction to occur that converts reactants to aproduct; and where the endothermic catalytic reactor apparatus isoptionally adapted to isolate the optional one or more second flammablematerials from a reaction taking place within the reactor and providingthe optional one or more second flammable materials to the burner, asdescribed above; and separating the product from non-product materialsas described above.

As will be apparent to those skilled in the art, the endothermiccatalytic reactor apparatus described herein can be used for a number ofendothermic processes, nonlimiting examples being cracking alkanes, thereaction of thionyl chloride with cobalt(II) sulfate heptahydrate, andthermal decomposition reactions. Nonlimiting specific examples alsoinclude conversion of ethane to ethylene, propane to propylene, ethylbenzene to styrene, ethyl toluene to vinyl toluene, and diethyl benzeneto divinyl benzene.

As a nonlimiting detailed example, the present disclosure provides amethod of producing styrene that includes passing a reactant stream thatincludes ethyl benzene and optionally super-heated steam through a heatexchanger to provide a heated reactant stream as described above at atemperature of from 450° C., such as 475° C. or 525° C. and up to 725°C., such as 675° C. or 625° C.; providing the reactant stream to anendothermic catalytic reactor apparatus as described above that includesa radiant furnace as described above that includes a burner as describedabove adapted to provide thermal energy to the furnace; a reactor,having any of the configurations described above, having a reactant feedline and a product discharge, situated within the furnace and adapted toreceive radiant thermal energy or heat from the furnace; one or morestatic helical spirals as described above that include a defined pathpositioned within the reactor so that a material can follow the definedpath to travel from the reactant feed line to the product discharge,where the helical spirals are adapted to hold a catalyst on an outersurface thereof as described above; one or more incoming ports on theentrance portion, adapted to receive the heated reactants; and a productdischarge on or near the exit portion, adapted to expel a product streamthat includes styrene from the reactor; where the reactor is adapted toallow the heated reactant stream to receive radiant thermal energy andinteract with the catalyst sufficiently to cause a reaction to occurthat converts ethyl benzene to styrene and byproduct hydrogen; where theproduct stream incudes styrene, hydrogen, optionally unreacted ethylbenzene and optionally steam; separating the product stream into aprimarily aqueous phase, a primarily organic phase and a non-condensableoverhead that includes hydrogen; separating styrene from the primarilyorganic phase as described above and optionally the primarily aqueousphase as described above.

As indicated above, the wall-to-reactant transfer can be so efficientthat the overall transfer between the radiant furnace and reactants mayonly be limited by the thermal conductivity and thickness of the reactorwall.

The conversion of ethyl benzene to styrene can be at least 70%, such as75% or 80% and can be up to 100%, such as, 99%, 95% or 90%. Theconversion of ethyl benzene to styrene can be any value or range betweenany of the values recited above.

As described above, styrene can be subsequently separated from theproduct stream.

The non-condensable hydrogen byproduct can be packaged using methodsknown in the art for subsequent uses, a nonlimiting example being use inelectric vehicles, fuel cells, batteries or to generate electricalenergy that could be used to supply the energy needed when burner 140 iselectric. As another alternative, the hydrogen could be used asflammable material in line 145 when burner 140 is a combustion burner.

As indicated above, the endothermic catalytic reactor apparatus andmethods described herein can be used to provide numerous products asdescribed above.

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentdisclosure may be made without departing from the invention as definedin the appended claims.

I claim:
 1. An endothermic catalytic reactor apparatus comprising: aradiant furnace comprising a burner adapted to provide thermal energy tothe furnace; a reactor, having an entrance portion and an exit portion,situated within the furnace and adapted to receive radiant thermalenergy from the furnace; one or more static helical spirals positionedwithin the reactor so that a material can follow a defined path totravel from the entrance portion to the exit portion, wherein thehelical spirals are adapted to hold a catalyst on an outer surfacethereof so as not impede the defined flow path; one or more incomingports on the entrance portion, adapted to receive reactive startingmaterials; and an exit port on or near the exit portion, adapted toexpel product from the reactor; wherein the reactor is adapted to allowthe starting materials to receive radiant thermal energy and interactwith the catalyst sufficiently to cause a reaction to occur thatconverts starting materials to product.
 2. The endothermic catalyticreactor apparatus according to claim 1, wherein the starting materialsare gaseous and flow along the defined path such that the startingmaterials have a Reynolds number of from 1,000,000 to 15,000,000.
 3. Theendothermic catalytic reactor apparatus according to claim 1, whereinthe starting materials are gaseous and flow along the defined path suchthat the starting materials have a Nusselt number of from 3,000 to15,000.
 4. The endothermic catalytic reactor apparatus according toclaim 1, wherein the starting materials pass through a heat exchangerprior to entering the reactor and enter the reactor at a temperature offrom 225° C. to 725° C.
 5. The endothermic catalytic reactor apparatusaccording to claim 1, wherein the starting materials have a mass flowrate through the reactor of from 20 kg/sec to 150 kg/sec.
 6. Theendothermic catalytic reactor apparatus according to claim 1, whereinthe starting materials have a volumetric flow rate through the reactorof from 500 l/sec to 1,000 l/sec.
 7. The endothermic catalytic reactorapparatus according to claim 1, wherein the starting materials have alinear velocity through the reactor of from 15 m/sec to 35 m/sec.
 8. Theendothermic catalytic reactor apparatus according to claim 1, whereinthe radiant furnace has a temperature of from 350° C. to 900° C.
 9. Theendothermic catalytic reactor apparatus according to claim 1, whereinthe conversion of starting materials to product is at least 10%.
 10. Theendothermic catalytic reactor apparatus according to claim 1, whereinthe starting materials and product are in their vapor phase when in thereactor.
 11. The endothermic catalytic reactor apparatus according toclaim 1, wherein the product is separated from non-product materials.12. The endothermic catalytic reactor apparatus according to claim 11,wherein the non-product materials comprise flammable materials that arecombusted in the burner.
 13. A method of converting reactants to productcomprising: passing reactants through a heat exchanger to provide heatedreactants at a temperature of from 225° C. to 725° C., providing heatedreactants to an endothermic catalytic reactor apparatus that comprises:a radiant furnace comprising a burner adapted to provide thermal energyto the furnace; a reactor, having an entrance portion and an exitportion, situated within the furnace and adapted to receive radiantthermal energy from the furnace; one or more static helical spiralspositioned within the reactor so that a material can follow a definedpath to travel from the entrance portion to the exit portion, whereinthe helical spirals are adapted to hold a catalyst on an outer surfacethereof; one or more incoming ports on the entrance portion, adapted toreceive the reactants; and an exit port on or near the exit portion,adapted to expel product from the reactor; wherein the reactor isadapted to allow the reactants to receive radiant thermal energy andinteract with the catalyst sufficiently to cause a reaction to occurthat converts reactants to a product; and separating the product fromnon-product materials; wherein the reactants have a mass flow ratethrough the reactor of from 20 kg/sec to 150 kg/sec.
 14. The methodaccording to claim 13, wherein the reactants are gaseous and flow alongthe defined path such that the reactants have a Reynolds number of from1,000,000 to 15,000,000.
 15. The method according to claim 13, whereinthe reactants are gaseous and flow along the defined path such that thereactants have a Nusselt number of from 3,000 to 15,000.
 16. A method ofproducing styrene comprising: passing a reactant stream comprising ethylbenzene through a heat exchanger to provide a heated reactant stream ata temperature of from 450° C. to 725° C.; providing the reactant streamto an endothermic catalytic reactor apparatus that comprises: a radiantfurnace comprising a burner adapted to provide thermal energy to thefurnace; a reactor, having an entrance portion and an exit portion,situated within the furnace and adapted to receive radiant thermalenergy from the furnace; one or more static helical spirals comprising adefined path positioned within the reactor so that a material can followthe defined path to travel from the entrance portion to the exitportion, wherein the helical spirals are adapted to hold a catalyst onan outer surface thereof; one or more incoming ports on the entranceportion, adapted to receive the heated reactant stream; and an exit porton or near the exit portion, adapted to expel a product streamcomprising styrene from the reactor; wherein the reactor is adapted toallow the heated reactant stream to receive radiant thermal energy andinteract with the catalyst sufficiently to cause a reaction to occurthat converts ethyl benzene to styrene and byproduct hydrogen; whereinthe product stream comprises styrene, hydrogen and optionally unreactedethyl benzene; separating the product stream into a primarily aqueousphase, a primarily organic phase and a non-condensable overheadcomprising hydrogen; separating styrene from the primarily organic phaseand optionally the primarily aqueous phase; wherein the conversion ofethyl benzene to styrene is at least 70%.
 17. The method according toclaim 16, wherein the heated reactant stream is gaseous and flows alongthe defined path such that the reactant stream has a Reynolds number offrom 1,000,000 to 15,000,000 and has a Nusselt number of from 3,000 to15,000.
 18. The method according to claim 16, wherein the styrene isseparated from the product stream.